What do you want to accomplish? You can change pretty much anything. You need to be careful with the cam, unless you're going to do a full DoD/AFM delete as well. With AFM, the max lift is limited to about 0.525" on the cylinders.

Drive it like you stole it, that's my suggestion! I put a CAI on mine, looked at a throttle body spacer, noticed there's a supercharger kit.
How much do you want to spend, how much do you want to gain? "It won't take too long, it'll just take money" as Alan Jackson puts it